Humidity

Humidity is the quantity of moisture (i.e., water vapor) in the air. It can be stated as absolute humidity or relative humidity. The absolute humidity is the mass of water vapor divided by a unit volume of air (i.e., grams of water/cm³ of air). The Relative humidity is the quantity of water vapor present in the air divided by the maximum quantity that the air could contain at that temperature. The Relative humidity is stated as a percentage. The relative humidity is 100% when the air is saturated with water vapor and 0% when no water vapor is present in the air at all.